Rip-cord puller for parachute packs



June 15, 1954 3nventor: JOHN L. ALLRED,

J. l ALLRED RIP-CORD FULLER-FOR PARACHUTE PACKS Filed Jan. 2, 1951 attornegs,

Patented June 15, 1954 UNITED STAT 1" RTENT OFFICE 13 Claims.

This invention relates to a rip-cord puller for parachute packs.

A principal object of the invention is to automatically impart operative motion to the ripcord of an aviation parachute pack in descending from an aeroplane or other aerial craft.

Important objects are:

(a) To be substantially universal in operation, which means that irrespective of the position occupied by the instrument in descending, the movement of the pulling element per se, will be effective to pull the rip-cord.

(b) To be simple and durable.

(c) To be light in weight.

(11) To be compact.

(e) To be reliably automatic in responding to timed setting for initiating the desired operation.

Still other objects will appear as the following description progresses.

Persons making parachute descents are frequently under certain degrees of nervous stress which conditions often make it diflicult, even if the person is experienced, to judge the proper time at which to pull the rip-cord of the parachute.

By means of the invention, the distance of falling at which it is desired to actuate the rip-cord, can be predetermined with a considerable degree of accuracy. The pulling element is actuated by means of stored elastic energy supplied for example by a spring. The point at which the pulling energy is released is determined by automatically disengaging a holding member such as a pawl, which in turn is subject to actuation adjustably with respect to variable, predetermined points. The adjustable mechanism is geared to the motion of a rotatable propeller which is actuated by contact with the air through which a descent takes place.

A feature of the invention is that the propeller is double acting, in other words is subject to bi-lateral motion, this being accomplished by blades or vanes set in opposing angular relationship axially with each other. Thus, the direction of rotative motion of the shaft on which the propeller is mounted, is constant. This causes the longitudinal travel of a member of the adjustable releasing mechanism to be constant in direction, irrespective of the position of the instrument in descending.

In the accompanying drawing which illustrates one embodiment of the invention:

Fig. 1 represents a typical position occupied by the instrument of the invention when held in the belt of a person using it;

Fig. 2, a side elevation largely in axial section taken along the line 2-2- in Fig. 5;

Fig. 3, a horizontal section taken on the line 33, in Fig. 2, this figure being largely in intermediate top plan;

Fig. 4, a fragmentary elevation looking in the direction of the arrow 4 in Fig. 2;

Fig. 5, a horizontal section taken on the line 5-5 in Fig. 2, this figure being largely in intermediate bottom plan;

Fig. 6, a top plan; and,

Fig. 7, a specific detail drawn to an enlarged scale.

Referring to the drawing: the numeral l0 denotes a tubular barrel which is rigidly held in the lower arm Ila of a primary frame Ii. At [2 is a secondary frame which is fast on the tubular barrel is at a point below the primary frame H. Journaled at E3, preferably by means of a depending hub, is a gear wheel it through which extends an axially slideable stem ES. The stem iii has a featherway [5a which is engaged by a feather key Eta fast in the hub of the gear It. Fast in the upper arm ill) of frame II is a tubular sleeve it which is slotted at lea. By means of the feather [3-11, the stem is is slideable axially in sleeve I6. At I? is a pin fixed in or integral with, a swivel sleeve Ila. The swivel Ila is loosely held on a fixed extension I50, while pin E's projects through the slot I'Ea. Thus, pin ll rises or descends, as the case may be, along with stem iii. In Fig. 7 swivel Ila rides on shoulder 15d of stem l5.

Meshing with the gear [4 is a pinion [8, the latter being mounted on a shaft [9 which, at its upper end, carries a propeller 20. The propeller is double acting, being made up of two superposed sections 20a. and 20b. Thus, a body of air through which the instrument is moving, will cause rotation of the shaft It in a constant direction no matter in which direction the propeller is rotating. This is illustrated in Fig. 2 where the propeller section 20a may be supposed to rotate in a given direction when acted upon by the body of air through which the person or object is falling in the direction of arrow 2 I. When the action of the body of air upon the person or object is reversed, as indicated by the arrow 21a, then the propeller section 2% acts to still rotate the shaft H9 in the same direction. Therefore it is clear that no matter in which direction the instrument is moving with respect to the propeller, the rotation of the shaft I9 is still constant in direction.

The lower part of the stem I5 is threaded as indicated at i512 and is normally engaged by a releasable nut 22 having handles 2211 which may be compressed inwardly around a pin 2213 as a fulcrum, so as to open jaws 23 which are threaded at 23a to normally efiect the aforesaid threaded engagement. The jaws 23 normally are held in the engaging position by means of a spring 24 which preferably is stiflly tensioned. The jaws 23 extend through a slot 25 in the barrel H). Fast in the secondary frame I2 is a tubular guide 2% having a fixed head 26a. through which the stem 2? has its movement. A compression spring 28 exerts its tension between the knob 21a and head Zta to jerk the stem 21 upwardly when it is free to do so. As shown in Fig. 2, the stem 2'i has been pulled down manually and is held in position opposed to the tension of spring 28 by means of a pawl 25 which has meanwhile come into engagement with the knob 21a by means of a groove Zlb which encircles the knob 21a. Pawl 29 is fulcrumed at 30 and is under an engaging tension by means of an axially coiled spring 3011.. The lower end of the pawl 29 is pivotally connected to a cupped trigger member 3! which is free to have a slight axial movement in the barrel it).

In operation, the instrument as shown in Fig. 2 is just ready to have the stem 2? released and thereby to cause its enlarged end 32 to be jerked up into the dotted position 32a. The rip-cord of a parachute (not shown) is suitably attached to the stem 21 so that the jerking action or" the spring 28 actuates the rip-cord for releasing the parachute. Now, supposing it is desired to reset the instrument for the next descent. The user grasps the handles 22a with the one hand, compresses them, thereby releasing the two-part nut from engagement with the stem and thus allowing the operator to grasp the pin H with the other hand and to freely pull the stem upwardly through the open nut until the pin has reached the desired gradation on the scale 35. The upward movement of the pin is conveniently stopped by a set collar 3%. In this position the user releases the handles 2211. so that the nut again engages the stem.

In the next descent the rotation of the propeller imparts motion to the gear l4 thereby in turn rotating the stem 25 by means of its sliding feather connection with the gear it. Rotation of the stem l draws it axially downward through the nut 22 until the lower end of the stem engages the trigger 3i and causes the latter to disengage the pawl 29 from the knob 27a thereby repeating the rip-cord releasing action previously described.

Heretoiore, various devices for operating the rip-cords of parachutes have been based on timing the interval at the expiration of which the operation takes place. Also, earlier devices have used so-called wind anchors which involve travel between the parachute and the anchor. Still other devices have employed clockwork or other mechanical means of determining a time interval, but so far as the present applicant knows, there has been no prior device in which a propeller that is actuated by passage through the air, is geared so that the distance through which the propeller, and hence the parachute also, falls, is used to determine the point at which the ripcord release is effected.

While the present disclosure is necessarily somewhat specific, it is to be understood that the scope of the invention is to be determined by the terminology of the following claims.

What is claimed is:

1. A parachute rip-cord puller comprising a puller rod; energy-storing means adapted to propel said rod; trigger means disposed to selectively hold said rod in opposition to the storedenergy stress; a propeller; and transmission mechanism including a trigger releaser intergeared with said propeller so as to cause said trigger releaser to approach said trigger means in rectilinear travel increments, whereby motion from said propeller becomes cumulatively operative to release said trigger means, the said trigger releaser being characterized by the inclusion of sto means selectively settable for contact by said trigger releaser in accordance any desired said travel increments.

2. A parachute rip-cord puller comprising a puller disposed for travel under influence of stored energy; trigger mechanism arranged to hold said puller selectively against the action of said stored energy, and again to release the same; and actuating means operative to release the trigger mechanism, which includes a rod disposed ror cumulative, axial travel thereof so as eventually to cause said rod to contact the trigger; and propeller means cumulatively geared to said rod, whereby to impart thereto the cumulative, axial travel necessary to eilect the eventual contact with said trigger, and settable stop means disposed to be contacted by said rod in its rctractive travel so as to predetermine the extent to which the selective hold upon said puller is exercised.

3. A rip-cord puller which includes a propeller; a rotatable shaft on which said propeller is mounted; a pinion on said shaft; a gear wheel in mesh with the pinion; a stem axially movable through the gear wheel but fixed for rotation therewith; and contact means operatively positioned between the stem and said trigger means.

4. A rip-cord puller according to claim 3, wherein is further included indicating mechanism operative to selectively determine a distance interval at the expiration of which interval, contact between the stem and the trigger means shall take place; and a disengager, operative to allow re-determination of said distance interval at any time by reducing to zero the said axial movement of the stem through the gear wheel.

5. A rip-cord puller according to claim 4, wherein said indicating means includes a swivel mounted on the axially movable stem; a pin extending from the swivel transverse to the axis of the stem; a slotted member in substantial axial alignment with the stem so as to engage said pin in the slot thereaof; and a graduated scale in registry with the pin.

6. A rip-cord puller according to claim 5, wherein the stem is threaded and wherein the ireaded portion is in engagement with a relatively fixed nut.

'7. A rip-cord puller according to claim 6, wherein said nut is split so as to be selectively disengageabie from the threaded portion.

8. A rip-cord puller according to claim '7, wherein the split nut comprises two parts pivoted together; a spring tensioned to normally hold the two parts in engagement with the threaded portion; and a handle extending from each of the two parts, the two handles being compressible in opposition to the spring tension.

9. An actuating mechanism, comprising an ax- I iaily movable actuator; means disposed to store energy for imparting motion to the actuator; en gaging means operative to hold the actuator in opposition to the stored energy; traveling means operative in axial motion to release the actuator from said engaging means; rotatable motive means geared to the traveling means; and stop means disposed for selectively determining the point at which said release of the actuator from the engaging means takes place, said stop means being settable, and at the same time being spaced apart from said actuator along the axis of the actuator.

10. Mechanism, wherein is included traveling means comprising an axially movable stem; a sleeve in which said stem is axially slidable; a pin extending transversely from the sleeve; a guide which constrains the pin to move axially of said stem; and set-collar stop means mounted to move axially of said sleeve so as to selectively engage said stop means.

11. An actuating mechanism, comprising a gear and a pinion in mesh with each other; a driver for the pinion; a rotatable stem on which said gear is longitudinally slidable and is fixed against rotation on the stem; means operative to cause the stem to move axially of the gear; a tensionable actuator; trigger means in registry with said stem and disposed to hold said actuator releasably in a tensioned position; and means operative to release said actuator from the trigger means.

12. A parachute rip-cord puller, comprising a propeller and shaft having a fixed pinion thereon;

a gear in mesh with said pinion; a bifurcated frame in which said shaft is journaled, and in the bifurcation of which the pinion and the gear are operatively disposed; a rotatable stem on which said gear is longitudinally slidable and is fixed against rotation thereon; means operative to cause said stem to move axially relatively to the gear; a tensionable actuator located in operative conjunction with the stem; and means operative to release the tensioned actuator.

13. The mechanism according to claim 12, wherein a secondary frame depends from said bifurcated frame and supports said actuator; wherein said stem is threaded; wherein the threads of the stem are engaged by a scissor nut; and wherein an arcuate spring is clasped over the jaws of the scissor nut, said arcuate spring being elfective to normally hold the jaws in the threadengaging position.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 377,602 Cooper Feb. 7, 1888 603,703 O'Connor May 10, 1898 1,081,984 Peel Dec. 23, 1913 2,098,613 Burgess Nov. 9, 1937 2,358,440 Bresee July 11, 1944 2,584,164 Stallan Feb. 5, 1952 

